WO2013085478A1

WO2013085478A1 - Grinding work member and centrifugal disintegrator based thereon

Info

Publication number: WO2013085478A1
Application number: PCT/UA2011/000128
Authority: WO
Inventors: Vladimir BUNETSKY; Stanislav REMENYAK
Original assignee: Bunetsky Vladimir; Remenyak Stanislav
Priority date: 2011-12-05
Filing date: 2011-12-26
Publication date: 2013-06-13

Abstract

Grinding work member has two coaxial counter- rotating shafts (2a, 2b). At least one shaft has axial opening for connection to a feeder. Two parallel disks (3a, 3b) fixed oppositely to the shafts and equipped with at least three arranged with radial clearances concentric grinding hoops (4a, 4b). Each hoop has at least two rows of rectangular in plan and trapeziform in cross - sections radially directed openings (5) confined by sharp edges. Linear dimensions of said openings in the arranged in series hoops and area of cross - section of each opening in any hoop decrease as far as the distances of theirs from common geometrical axis increase. This minimizes energy consumption when materials having high impact resistance will be disintegrating. Centrifugal disintegrator has housing, at least one said work member, feeder connected to the said axial opening, and at least one tangential branch pipe (6) for aspiration of disintegrated products.

Description

G RI N DI NG WORK M EM B ER

AN D C E NTRI F UGAL D I SI NTEGRATO R BASED TH E R EO N

Field of the Invention

This invention relates to a structure of grinding work member and through-flow centrifugal disintegrator based thereon. They meant for disintegration of organic (preferably vegetable) materials, such as:

wood waste (that includes, as a rule, significant lignin admixtures);

agricultural waste, such as cereal straw, flax stock, stems of maize, sunflower or cotton- plants, husks of seeds of oil plants, nutshells etc.;

dewatered peat, tree waste, algae etc.

In addition, disintegrator may use for grinding of preliminary crushed wastes of articles made from preferably thermosetting (including reinforced) plastics.

Obtained polydisperse mechano-chemically activated powders can compound immediately after disintegration with suitable binding agents and, optionally, with suitable fillers, and then press or extrude at temperature usually less than 100°C in various articles, such as: fuel granules, briquettes or slugs meant for combustion in industrial and home heat- generators,

solid or hollow (usually shaped) constructional materials meant for use in building industry, machine building and furniture factories.

Background Art

Growing deficiency of fuel resources and prospective decrease of delivery of organic minerals for synthesis of monomers and oligomers are very appreciable. Therefore, engineers search effective means for disintegration and following reprocessing of many organic wastes in artificial energy carriers and environmentally harmless substitutes of synthetic polymers.

However, organic wastes have very various chemical compositions, physical-chemical and mechanical properties. Thus, machines for disintegration of said wastes before utilization are usually ad-hoc developed against specified raw and function of final products.

For instance, RU 2397020 discloses disintegrator of oil-containing wastes, i.e. oil-slimes and water-oil emulsions. It has a stepped hollow cylindrical housing, a work member based on two disk-shaped rotors fixed onto coaxial hollow shafts and oppositely placed within annular chamber of said housing, and a counter-rotation drive of said rotors. Each rotor is equipped with a few concentric rows of impact grinding elements in the form of symmetrical paddles having sharp edges. Each paddle confined by internal concave surface and external convex surface. The internal concave surfaces of the paddles of each rotor oriented oppositely to direction of rotation of this rotor in order to generation of turbulent counter-flow of processing material and its cavitational disintegration. It is clear for each person skilled in the art that any disintegrator equipped with said work member can make only stable emulsions of viscous substances in fluid dispersive media but is not capable to disintegrate hard wastes.

Similarly, "Bale processor with feed cutter" according to the US 7,546,966 is meant for cutting of cereal straw (used, especially, as stover), but is not suitable for fine grinding of wood wastes, nutshells, husks of sunflower seeds, peat and the like vegetable materials.

Disintegration of theirs can make «Disruptor system for dry cellulosic materials* disclosed in US 7,954,734. This system performs - preliminary crushing of biomass (particularly, wood, agricultural vegetable wastes and the like materials) and obtaining of chips having maximal size about 10 mm,

drying of these chips up to residual moisture no more than 15% by weight,

preliminary grinding of the dried chips and obtaining of particles having maximal size no more than 1 mm, and

their disintegration using a disk mill in order to obtain aerosols containing such micro- powders, particles of which have sizes in the range from 5 to 10 micrometers, and preferably less than 1 micrometer.

The same patent specification discloses two aspects of use of obtained products, namely: either biochemical or chemical hydrolysis of cellulose-containing micro-powders separated from aerosols in order to obtain a mixture of saccharides or combustion of said aerosols in order to generate heat.

Unfortunately, lignin admixtures substantially complicate even chemical hydrolysis of wood micro-powders and extraction of saccharides from reaction mixture, whereas combustion of said aerosols is unprofitable because preparation of micro-powders requires substantial energy expenditure. Moreover, long-distance transportation of such aerosols is unreasonable, and separation of extremely fine-dispersed combustive particles is very difficult.

At present, it has known that fuel granules, briquettes and slugs or other tight articles can make on basis of such mechano-chemically activated powders of cellulose-containing materials, which have particles' sizes in the range from 0.05 mm to 0.1 mm and more.

In particular, such powders must be slightly wetted in order to make required articles by pressure molding or extrusion (see EYHEL-lbKHM B.A., Ukrainian Patent No. 54540 U «TexHonorNHa JiiHm 3Bono>KeHoro npecyeaHHfl ποΑρίοΉβΗθϊ opraHiKM»; in English: BUNETSKY, Vladimir «Processing line for dampened pressing of grinded organic matters»).

Unfortunately, vegetable wastes have the greater impact resistance the higher is degree of polymerization of cellulose containing in their chemical composition and the more obvious is their fibrous structure. Hence, inventors must aspire to minimization of energy expenditure for disintegration of vegetable or other polymeric wastes having high impact resistance. Majority of attempts to achieve this purpose were based on improvement of disk disintegrators having rod-shaped impact grinding elements (see., for example: SU 908383, SU 1560313, SU 1572694, SU 1694211 , RU 2291745, WO 9107223 A1 , GB 2047104 A etc.).

In particular, RU 2353431 C1 discloses a grinding work member and a disintegrator, which are the nearest to the proposed below devices.

Known grinding work member has upper and lower horizontal disks. They equipped with shafts, one of which has an axial opening meant for supply of raw. A few concentric rows of rod- shaped impact grinding elements had rigidly fixed onto opposite sides of said disks. In operative position, the rows of said grinding elements of said upper disk had placed between the rows of said grinding elements of said lower disks.

Known disintegrator comprises of:

a hollow stepped cylindrical housing,

a mounted in this housing above-described grinding work member,

a feeder connected to the axial opening in said shaft and meant for continuous delivery of preliminary prepared raw;

a tangential branch pipe meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium (that is usually atmospheric air), and

a counter-rotation drive of said grinding disks.

The described disintegrator grinds hard particles preferably owing to mechanical impacts of theirs with rod-shaped grinding elements, whereas mutual impacts of said particles are rather infrequent. It is admissible in case of disintegration of brittle minerals such as finely broken stone or sand, but is unprofitable in case of disintegration of vegetable wastes having high impact resistance. Moreover, substantial part of drive energy spends in order to overcome pneumatic resistance that causes by the rod-shaped grinding elements.

Summary of the Invention

This invention based on the problem to create - by improvement of shapes and relative position of grinding elements - such grinding work member and such centrifugal disintegrator based thereon, which could intensify mutual impacts of hard particles and, thereby, decrease expenditure of energy.

At first, this problem has solved in that a grinding work member according to the invention comprises of:

two practically coaxial shafts, which meant for connection to a counter-rotation drive and at least one of which has an axial opening connected, in operative position, with a feeder for supply of a raw material for disintegration,

two practically parallel disks fixed to the opposite end parts of said shafts, and

at least three arranged with radial clearances concentric grinding hoops, each of which is rigidly connected by one of its end with one of said disks and has at least two rows of rectangular in plan and trapeziform in cross-sections radially directed openings confined by sharp edges; at that linear dimensions of said openings in the arranged in series grinding hoops and area of cross-section of each opening in any grinding hoop are decreased as far as the distances of theirs from common geometrical axis increase.

Sharp edges of said openings efficiently cut particles of fibrous vegetable wastes, which move in air stream from geometrical axis of said disks to their periphery, and high-speed turbulent air swirls within clearances between each pairs of neighboring grinding hoops of the different disks provide multiple non-elastic collisions of grindable particles. Respectively, disintegration of hard wastes having high impact resistance requires substantially lesser expenditure of energy.

First additional feature consists in that the disks are practically vertical. This facilitates delivery of raw into disintegration zone and aspiration of disintegrated particles.

Second additional feature consists in that the grinding hoops fixed onto at least one of said disks have riffles located on at least one side of each said hoop. This intensifies turbulization of aerosol in clearances between the hoops of the different disks.

Third additional feature consists in that the openings in the grinding hoops have quadratic form in plan and arrange more than in two rows. This allows most effectively disintegrate wood wastes such as small wood chips and, especially, sawdust.

Fourth and fifth additional features consists, respectively, in that the grinding work member is equipped either with replaceable in whole disks, or with replaceable grinding hoops only. These features allow to enhance repairability of each disintegrator that equipped with any grinding work member according to the invention and, as needed, to adapt such disintegrator to processing of different raw materials having various mechanical properties.

Above-mentioned problem has solved also in that a centrifugal disintegrator according to the invention comprises of:

(a) a hollow stepped cylindrical housing;

(b) a mounted in this housing at least one grinding work member that comprises of:

at least three arranged with radial clearances concentric grinding hoops, each of which is rigidly connected by one of its end with one of said disks and has at least two rows of rectangular in plan and trapeziform in cross-sections radially directed openings confined by sharp edges; at that linear dimensions of said openings in the arranged in series grinding hoops and area of cross-section of each opening in any grinding hoop are decreased as far as the distances of theirs from common geometrical axis increase;

(c) a feeder connected to the axial opening in at least one of said shafts and meant for continuous delivery of preliminary prepared raw;

(d) at least one tangential branch pipe meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium, and

(e) a counter-rotation drive of said disks of said grinding work member.

Equipping of the through-flow centrifugal disintegrator by the grinding work member according to the invention provides substantial decreasing of energy expenditure, when organic wastes having high impact resistance would be disintegrating.

Additional feature consists in that said centrifugal disintegrator equipped with at least two located on practically equal angular distances tangential branch pipes meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium. This facilitates aspiration of disintegrated products.

Brief Description of Drawings

This invention will now have explained by detailed description of structures and operation of proposed devices with references to accompanying drawings, in which:

Fig.1 shows a single-sectional centrifugal disintegrator (longitudinal section by vertical symmetry plane);

Fig.2 shows an example of the grinding work member's disk (axonometric view, on which only an external grinding hoop is visible);

Fig.3 shows an example of arrangement of four grinding hoops within the grinding work member, in which each disk is equipped with two said hoops (cross section by vertical plane);

Fig.4 shows the fragment «K» from the Fig.3 on a large scale.

Best Embodiments of the Invention

A simplest single-sectional centrifugal disintegrator comprises of (see. Fig.1 ):

A hollow stepped cylindrical housing 1 ;

A grinding work member that has mounted in the housing 1 and comprises of:

- two practically coaxial (preferably horizontal) shafts 2a and 2b, which meant for connection to a mentioned below counter-rotation drive and at least one of which (e.g., 2a) has an axial opening connected, in operative position, with a mentioned below feeder for supply of a raw material for disintegration,

- two practically parallel (and, preferably, vertical) disks 3a and 3b fixed to the opposite end parts of said shafts 2a and 2b, and

- at least three arranged with radial clearances concentric grinding hoops 4a and 4b, each of which is rigidly connected by one of its end with one of said disks 3a or 3b and has at least two rows of rectangular in plan and trapeziform in cross-sections radially directed openings 5 confined by sharp edges; at that linear dimensions of said openings 5 in the arranged in series grinding hoops 4a and 4b and area of cross-section of each opening 5 in any grinding hoop 4a and 4b are decreased as far as the distances of theirs from common geometrical axis increase (see additionally Figs 3 and 4);

A suitable (e.g., screw or flow) feeder that has connected, in operative position, to the axial opening in at least one shaft (especially, 2a) of the grinding work member and meant for continuous delivery of preliminary prepared raw (this feeder conditionally showed on Fig.1 by thick axial arrow);

At least one tangential branch pipe 6 meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium (usually with atmospheric air) using not showed here a suction fan, and

A counter-rotation drive of said shafts 2a and 2b of said grinding work member (this drive conditionally showed on Fig.1 by two oppositely directed curved arrows).

In practice, dimensions of the openings 5 in the grinding hoops 4a and 4b select such that clearance between them would be sufficient for passage of initial and intermediate particles of any raw materials, which must usually crush before supply into a disintegrator using, for example, straw cutter, chipper, shredder, impact crusher etc. Usually, dimensions of the openings 5 in first (i.e. nearest to the geometrical axis of the grinding work member) grinding hoop 4a must be sufficient for passage of raw particles having maximal size no more than 10 mm (and, preferably, no more than 5.0 mm), and maximal dimension of the openings 5 in the last grinding hoop 4a or 4b is usually less than 1 mm (preferably 0.5 mm).

It is desirable, if grinding hoops 4a and/or 4b at least have on one side not shown especially riffles between axially oriented rows of the openings 5, as it has shown on Figs 2 and 4. It is also desirable, if the openings 5 in the grinding hoops 4a and 4b have quadratic form in plan and arrange more than in two rows. In addition, either the disks 3a and 3b in whole, or only the grinding hoops 4 can be replaceable. For example, Fig.2 shows the disk 3 that has two replaceable concentric grinding hoops 4 mounted on pins 7.

Further, the centrifugal disintegrator can be equipped with not especially shown at least two located on practically equal angular distances tangential branch pipes meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium immediately or through not shown especially collecting channel.

Centrifugal disintegrator operates as follows.

Preliminary crushed raw goes into the communicating with atmosphere axial opening in the shaft 2a (or into the openings of both shafts 2). Draft provided by a not shown especially suction fan at the disintegrator output creates aerosol that composed of initial hard particles and air and goes under the first lower grinding hoop 4a.

Then aspiration of air draws initial hard particles into the openings 5 of this hoop 4a. Because next grinding hoop 4b is counter-rotating, air in the clearance between said hoops 4a and 4b presses said initial hard particles to the sharp edges of first hoop 4a, which cut these particles. High-speed turbulent air swirls within clearances between neighboring first and second grinding hoops 4a and 4b of the different disks 3a and 3b provide multiple non-elastic collisions of grindable particles and intensive additional disintegration of theirs.

Similarly, sharp edges of the openings 5 in second grinding hoop 4b cut said intermediate products of preliminary grinding. Further still more small fragments collide intensively in high-speed turbulent air swirls between neighboring first and second grinding hoops 4b and 4a of the different disks 3a and 3b and again disintegrate.

Analogous processes occur in cases, if any grinding work member has more than three grinding hoops. Disintegration finishes only in relatively laminar stream of aerosol on outlet from tangential branch pipe 6.

Practicability of the invention had verified experimentally. Thereto, replaceable disks 3a and 3b providing in operative positions different radial clearances between neighboring grinding hoops 4a and 4b had made. In particular, trials had carried out using three sets of said disks, which had equipped respectively: (I) with two hoops 4a and one hoop 4b; (II) with three hoops 4a and two hoops 4b; and (III) with four hoops 4a and three hoops 4b.

External diameters of experimental hoops 4a and 4b were selected in the range from 560 mm to 650 mm, and their thickness were selected in the range from 4.0 mm to 10.0 mm. Sequentially decreasing radial clearances between neighboring hoops 4a and 4b had selected in the range from 5.0 to 1.0 mm with the pitch 0.5 mm.

Tests show, that average dimension of disintegrated particles at the output from each serial annular clearance between two neighboring grinding hoops 4 and particles of finished product behind the last grinding hoop 4 will be the smaller the narrower annular clearance AS between two neighboring counter-rotating hoops 4. In the general case, this annular clearance can define according to the empirical formula

AS≤ 0.01 d _K,

where d_K is the internal diameter of such grinding hoop 4, which envelopes a previous hoop 4 in each pair of neighboring hoops (e.g. 4a and 4b or inversely).

Disclosed in RU 2353431 disintegrator-prototype, disks of which were equipped with two rows of said rod-shaped impact grinding elements, had made too.

Cut wheat straw, particles of which had initial dimensions in the range from 1 mm to 5 mm, had used for comparative trials of said two disintegrators. In all tests rotary axis speed of disks was equal 3000 rpm, and raw materials consumption was equal 1 kg/s. Resulting information specified below in the table.

Table RES U LTIN G I NFORMATI ON ABOUT COM PARATIVE TRIALS

OF DI S I NTEGRATORS HAVI NG DI FFERENT GR I N DI NG WORK MEM B ERS

It is clear for each person skilled in the art - that above described and illustrated by drawings embodiments of the invention include only basic information required for production and use of new grinding work members and centrifugal disintegrators, and

that conception of invention may be supplementing and/or specifying on basis of general engineering knowledge within the defined by following claims scope of rights.

For example, a disintegrator may have two (or more) grinding sections, each of which has one grinding work member and which can be connected in series or in-parallel, and may be equipped with usual controlling means and safety shutdown.

Industrial Applicability

Any embodiment of the invention can realize industrially using known materials, equipment and tool set.

Use of any disintegrator having above-proposed grinding work member based on perforated grinding hoops allows decreasing power inputs on the average 30%.

Claims

C LA I M S

1. Grinding work member, comprising:

2. Grinding work member according to the claim 1 , wherein said disks are practically vertical.

3. Grinding work member according to the claim 1 , or to the claim 2, wherein the grinding hoops fixed onto at least one of said disks have riffles located on at least one side of each said hoop.

4. Grinding work member according to the claim 1 , or to the claim 2, or to the claim 2, wherein the openings in the grinding hoops have quadratic form in plan and arrange more than in two rows.

5. Grinding work member according to the claim 1 , which is equipped with replaceable in whole disks.

6. Grinding work member according to the claim 1 , wherein said disks are equipped with replaceable grinding hoops.

7. Centrifugal disintegrator, comprising:

(a) a hollow stepped cylindrical housing;

(e) a counter-rotation drive of said disks of said grinding work member.

8. Centrifugal disintegrator according to the claim 7, which is equipped with at least two located on practically equal angular distances tangential branch pipes meant for continuous aspiration of a mixture of hard disintegrated products together with gaseous disperse medium.